Mechanical gyroscopes with a spinning rotor or flywheel are used in many autonomous vehicles such as airplanes, satellites, and missiles. Because in most of these applications space is at a premium, it is desirable to have gyroscopes as small as possible, while retaining sufficient accuracy for the application. In addition, particularly for space vehicles, weight is a major concern.
Gyroscopes for these applications typically employ a rotated disc or sphere that rotates on mechanical or hydrodynamic bearings. The required number of parts and tolerances between the parts dictates the smallest possible size that can be attained using machining fabrication processes. The motor used to spin the rotor, and the sensors and actuators used to control the position of the rotor, then must be made commensurate in size with the rotor; the motor must be large enough to develop the torque necessary to control the mass of the rotor.
The rotor rotational rate of these gyros is typically on the order of only 50,000 rpm in order to limit the kinetic energy so that the rotors can be properly contained, and minimize problems associated with catastrophic rotor failure. However, it is desirable to spin the gyroscope rotors at the highest possible rate because the accuracy of the gyroscope is related to the rotor rotational velocity. In addition, the relatively large rotor mass creates a relatively high demand for power in these gyroscopes, both to spin the rotor and control its position. Accordingly, there is a great need for a much smaller gyroscope having very high rotor rotational speed and decreased power demand.
There are other applications for gyroscopes, such as in guided automobiles, that do not place such a premium on gyroscope size, weight, or power demands, although these are always concerns. However, to make the use of gyroscopes practical for such devices, there cost must be minimal. The present day machined gyroscopes require at least some manual machining steps, cleaning and assembly. Accordingly, gyroscopes to date have been essentially custom produced devices that are extremely expensive and so not practical for myriad desired uses.